What does loss of proprioception tell you clinically?
Doesn't localize the lesion, but a sensitive indication of a neurological problem (anywhere along the proprioceptive pathway: peripheral nerves, spinal cord, brain stem, cerebrum, or cerebellum)
Complete loss of motor activity
Weakness, partial loss of voluntary motor activity
What are the suffixes -paresis and -plegia used to describe?
Paresis and paralysis, respectively
Differentiate flaccid and spastic paresis or paralysis.
Flaccid: decreased or no tone in muscles
Spastic: increased tone/hypertonicity
Lack of coordinated movements with or without spasticity or paresis
What can cause ataxia?
Lesions of the entire NS may cause ataxia. Although not specific, it shows up frequently and is indicative of a NS problem.
Define intention tremor and what it indicates.
A tremor (sma,, rapid, alternating movements at rest) that becomes worse with initiation of a movement and disappears at rest
Indicates cerebellar disease
Involuntary movement of the eyes in either a rotatory, vertical, or horizontal direction
How does nystagmus at rest appear and what does it indicate?
Eyes move to the side of lesion and snap back
Abnormality, usually indicates vestibular dysfunction
Dysmetria and what does it indicate?
Improper measuring of distance in muscular activity, too short or too long (i.e. goose stepping)
Indicates cerebellar disease
How do you screen for neurological problems?
Mental attitude/consciousness, behavior, seizures
Stance and head position
Gait and strength
Why is mental attitude/consciousness, behavior, seizures observed in a neuroscreening test?
Screen for cerebrum and brain stem problems.
What does observation of stance and head position of a neuroscreening test check?
What abnormal stance and head position indicate neurological problems (cerebellum/vestibular system)?
Head tilt, wide based stance; head tremor/bobbing
What does gait and strength observation evaluate?
What is gait checked for during a neurological screening test?
Peoprioceptive deficits, paresis circling, ataxia and dysmetria, scuffing, knuckling or atrophy
What does abnormalities in gait indicate in a neurological screening?
NS problem (cerebrum, cerebellum, brain stem, spinal cord, peripheral nerves, or vestibular lesions
Do gait abnormalities localize a neurological lesion?
No, just a neurological problem that can be anywhere: cerebrum, cerebellum, brain stem, spinal cord, peripheral nerves, or vestibular system
How is strength tested during a neurological exam?
Push down on the standing animal
What does weakness indicate during a neuorlogical screening?
Nervous problem somewhere other than the cerebellum or peripheral vestibular system (cerebrum, brain stem or spinal cord injuries, peripheral nerves)
What is the only part of the nervous system that will not result in weakness?
Cerebellum (& peripheral vestibular system)
What is the most common postural reaction used to screen for neurological problems?
Proprioceptive positioning (knuckling)
What is a neuroscreening test to indicate there is a neurological problem but doesn't localize where the problem is?
Proprioceptive positioning (knuckling), postural reaction (also gait and strength observation)
For what does proprioceptive positioning test?
Conscious perception of the location of the limbs
What does loss of proprioception tell you clincally?
Doesn't localize the lesion, but is a sensitive indication of a neurological problem (anywhere along the proprioceptive pathway: peripheral nerves, spinal cord, brain stem, cerebrum, or cerebellum)
What is done once screening indicates a neurological problem?
Other procedures done to localize the lesion to a specific part of the nervous system
What is a CSF tap and where is it done?
Removal of cerebrospinal fluid from the subarachnoid space in the cisterna magna or lumbar cistern
What is epidural anesthesia, where is it commonly given?
Anesthetize the spinal nerves in the area, through the lumbosacral opening (L7-S1) into the epidural space
What is the affect of UMNs damage on LMNs?
LMNs increase their activity
To where do LMN signs localize the lesion?
Peripheral nerves, spinal cord, or segment of brain stem the LMN arises from
Flaccid paresis or paralysis
Decreased or no tone with paresis or paralysis due to lesions of LMNs
Spastic paresis or paralysis
Extra tone (hypertonicity) with paresis or paralysis due to lesions of UMNs
What does pointing your thumb down in LMN damage indicate?
Everything decreased or disappears
4 LMN disease signs (thumb down)
Decreased or absent tone (hypo- to areflexia)
Decreased to absent reflexes (hypo- to areflexia)
Rapid atrophy (neurogenic atrophy); usually 1 week
4 UMN disease signs (thumb up)
Normal to increased muscle tone
Normal to increased reflexes (hypereflexia)
Spastic paresis or paralysis
Slow (disuse) atrophy
List how the reflexes are checked for the limbs.
How is a withdrawal reflex performed?
Pinch (pain) the toe; normal response = withdrawal of the limb
How is tone evaluated?
Palpate the muscles of the limbs
Localize the lesions: flaccid paralysis, absent reflexes and tone, and rapid atrophy to the pelvic limbs with normal thoracic limbs.
L4-S1 spinal cord lesion (area 4) (LMN signs to pelvic limbs, normal thoracic limbs)
Localize the lesion: spastic paresis, increased reflexes and tone to the left pelvic limb and flaccid paralysis, decreased reflexes and tone to the left thoracic limb
Unilateral C6-T1 (area 2) on the left (LMN: left thoracic and UMN: left pelvic limb)
Localize the lesion: spastic paresis, increased reflexes and increased tone to all limbs
Lesion crnial to C6 (area 1)
Localize the lesion: spastic paresis, increased reflexes and tone to the pelvic limbs, and normal thoracic limbs
T3-L3 (area 3) (UMN: P limbs; Normal = Shiff-Sherington)
Presenting signs of C1-5 spinal cord
All 4 limbs: UMN (thumbs up) (no LMN signs to any limb)
Presenting sings of cervical enlargement, C6-T2
Pelvic limbs: UMN (thumb up)
Thoracic limbs: LMN (thumb down)
Presenting signs of T3-L3
Pelvic limb: UMN (thumb up)
Thoracic limb: no effect (+/- Shiff;Sherington)
Presenting signs of L4-S1
Pelvic limb: LMN (thumb down)
Thoracic limb: no effect
What causes a coma?
Complete disconnection of the reticular activation system from the cerebral cortex, usually due to a severe brain stem lesion
List 3 primary deficits that may be seen with lesions to the cerebrum?
Behavior and mentation abnormalities
Abnormal posture with normal gait
Blind with normal pupillary reflexes
Complusive pacing, head pressing
Unilateral cerebral lesions will cause _____ signs?
How is brain stem disease characterized?
Abnormal gait and abnormal posture and cranial nerve deficits, decreased mental states, proprioception deficits and weakness
What is the range of decreased levels of consciousness due to brainstem lesions?
Depression to coma
What is the best evidence of brainstem lesions?
Multiple dysfunction of cranial nerves 3-12
When should brain stem disease be suspected?
If cranial nerves abnormalities, UMN paresis, or decreased consciousness
How does a cerebellar lesion present?
Uncoordinated without paresis (no weakness), proprioceptive deficits vestibular signs
What do vestibular system lesions affect?
The ability to control posture in relationship to gravity and eye movements in relationship to head movements
What are signs of vestibular disease?
Head tilt, nystagmus, asymmetric ataxia with possible circling
What is the primary diagnostic concern with vestibular disease?
Differentiating peripheral (no pareses or depression) from central (paresis and depression) vestibular disease
What is the first deficit to show with a neurological deficit?
What does BAR stand for?
Bright, alert, and responsive
What does multiple dysfunction of cranial nerves indicate?
Brain stem lesion
What would cause a dropped jaw?
Paralysis of trigeminal nerve
Why is paralysis of the orbicuaris oculi and loss of lacrimation the most vital results of facial nerve paralysis?
Drying the eye; animals are not vain (facial paralysis)
How is auricopalpebral nerve manipulated clinically? In what species?
Blocked to paralyze eyelids for eye procedures; large animals
How is the facial nerve commonly injured in the horse?
Lying on a halter buckle during surgery (buccal on buckle)
Optic nerve (2)
Complaint: Anisocoria (unequal sized pupils)
Sympathetic, parasympathetic (3)
Complaint: Strabismus (uncontrolled deviation of the eye)
Oculomotor (3), trochlear (4), abducens (5)
Complaint: Dropped jaw and head atrophy
Trigeminal nerve (5)
Complaint: increased or decreased facial sensation
Trigeminal nerve (5)
Complaint: facial paralysis
Facial nerve (7)
Complaint: Deafness and/or loss of balance
Vestibulocochlear nerve (8) damage
Complaint: Dysphagia (difficult swallowing)
Glossopharyngeal (9), vagus (10)
Complaint: Laryngeal paralysis
Vagus (10), recurrent laryngeal nerve
Complaint: paralysis of the tongue
Paralysis of which nerve results in a weak tongue?
How is the facial/trigeminal reflex arc checked?
Prick the face, pulling away indicates intact trigeminal nerve, twitch of face muscles indicate intact facial nerve
What cranial nerve problem can be seen with middle ear infections?
Paralysis of the facial nerve and resulting dry eye
What procedure can be used to facilitate the exam of the eye? How?
Auriculopalpebral nerve block, eliminates blinking and closing of the eye (rare in dogs, common in horses)
What are signs of damage to the recurrent laryngeal nerve?
Laryngeal paralysis/hemiplegia: failure of the glottic cleft to open
Seen in horses (roarers) and dogs - high pitched, whistling on inspiration and exercise intolerance occur
Discuss the clinical significance of the accessory nerve (XI)
Little clinical significance
Describe the pupillary light reflex and what structures it involves?
Shining a light in the eye, noting if the pupil constricts in that eye and then the other eye; checks both cranial nerves II and III (optic and oculomotor nerves)
Describe the signs of facial nerve (VII) damage
Paralysis of the muscles of facial expression resulting in a distorted face, paralysis of the orbicularis oculi muscle and if proximal enough, the ANS fibers to the lacrimal gland, thus, can result in a dry eye
What is dysfunction of the sympathetic fibers to the eye?
List the cardinal signs of Horner's syndrome
Miosis (small pupil)
Enophthalmos (small eyes)
Ptosis (drooping eyelid)
Protrusion of nictitating membrane
What results in swelling or draining (pus) below the carnivore's eye?
Carnassial tooth abcess (upper premolar 4)
How is aging of dog by their teeth used practically in dogs?
Baby teeth in by 6 weeks: vaccination time
Adult by 6 months: spay/neuter time
Which dog teeth have three roots?
Last 3 on top
Which cat permanent teeth have 3 roots?
Upper PM 4 (carnassial)
How is a nasogastric tube placed?
Through the nostril and the ventral nasal meatus or it will break the ethmoid turbinates, resulting in nasal bleeding (epitaxis)
A laryngotomy to open the larynx goes through which paired muscles to expose the larynx?
Sternohyoid muscles, middle "strap" muscle
The esophagus is accessible to surgery in the ____ half of the neck region on the _____ side.
What surgical landmark indicates the ventral midline of the larynx?
Cricothyroideus or bowtie muscle
Paralysis of what muscle results in 'roarers' in horses
Cricoarytenoideus dorsalis muscle
How is a tranqulized dog intubated?
Gently pull the tongue rostrally, push the soft palate up with the endotracheal tube, hold the epiglottis down with the tube, direct tube between the vocal folds into the trachea
What causes laryngeal paralysis (dogs and horses)?
Damage to the recurrent laryngeal nerve resulting in paralysis of the cricoarytenoideus dorsalis muscle, the only muscle to open the glottic cleft, producing a roaring sound when breathing
What is a roarer?
Dog or horse with laryngeal paralysis due to the recurrent laryngeal nerve damage and resulting paralysis of the cricoarytenoideus dorsalis muscle